High firing rate hypervelocity gun and ammunition therefor



D. DARDICK March 31, 1970 HIGH FIRING RATE HYPERVELOCITY GUN ANDAMMUNITION THEREFOR I Filed Sept. 1, 1967 3 Sheets-Sheet 1 March 31,1970 o. DARDICK 3,503,300

HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR Filed Sept.1, 1967 3 Sheets-Sheet 2 1 \"VENI'OR 04:00 04:04

Jrraemey March 31, 1970 D. DARDICK 3,503,300

HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR Filed Sept.1, 1967 3 Sheets-Sheet 3 zg'yda INVENTOR. filly/0 04m United StatesPatent O 3,503,300 HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITIONTHEREFOR David Dardick, Palos Verdes Peninsula, Calif., assignor to TRWInc., Redondo Beach, Calif., a corporation of Ohio Filed Sept. 1, 1967,Ser. No. 665,155 Int. Cl. F41d 11/14 US. Cl. 89-8 20 Claims ABSTRACT OFTHE DISCLOSURE A high firing rate hypervelocity gun having at least onebarrel, a primary breech mechanism at the breech end of the barrel forsuccessively transporting primary rounds to and firing each round infiring position to eiiect forward propulsion of its projectile throughthe barrel, and at least one secondary breech mechanism located at abooster station along the barrel forwardly of the primary mechanism forsuccessively transporting booster rounds to firing positionsimultaneously with the primary rounds in such manner that thepropellant charge in each booster round is exposed to and ignited by thepropellant gas generated by the corresponding fired primary round uponforward travel of its projectile through the respective booster station,thereby to increase the propellant gas pressure behind the projectileand accelerate the latter through the barrel. Booster ammunition for thehypervelocity gun.

REFERENCE TO COPENDING APPLICATIONS Reference is made herein tocopending applications, Ser. No. 671,910, filed Sept. 1, 1967, andentitled Sealed Open Chamber Breech Mechanism and Caseless AmmunitionTherefor, and Ser. No. 665,136, filed Sept. 1, 1967, and entitledSemicombustible Ammunition for Open Chamber Breech Mechanism, nowabandoned.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates generally to guns and more particularly to so-calledhypervelocity guns. The invention relates also to novel ammunition forthe guns.

Prior art Hypervelocity guns are known in the art and, as their nameimplies, are characterized by extremely high muzzle velocity, i.e.,hypervelocity. Such hyper-muzzle velocity may be achieved in variousways. The present invention is concerned with the particularhypervelocity technique which involves ignition of a booster charge atone or more positions along the bore directly behind the advancingprojectile to increase or boost the propellant gas pressure behind theprojectile and thereby accelerate the latter through the bore to ahypervelocity.

Hypervelocity guns which utilize this booster firing technique toachieve hyper-muzzle velocities have been devised. Generally speaking,such guns comprise a barrel with a breech mechanism for firing a primaryround at the breech end of the barrel. This primary round contains aprojectile which is propelled forwardly through the barrel by thepropellant gas pressure generated by firing of the round. Arranged alongthe barrel, forwardly of the breech mechanism, are one or more secondaryor booster firing chambers containing a'booster propellant charge. Eachbooster chamber communicates to the bore in the gun barrel through portsin the barrel wall. As the projectile travels forwardly past eachbooster chamber, its contained booster charge is exposed to and ignitedby the high temperature propellant gas of the fired primary round. Thepropellant gas generated by the burning booster charge then enters thebore to increase the total propellant gas pressure behind the projectileand thereby accelerate the latter through the bore.

While this type of gun achieves a hyper-muzzle velocity, it has certaininherent deficiencies. The major deficiency of the gun, for example,resides in the fact that reloading is very laborious and time consuming.As a consequence, hypervelocity guns of the characteristic describedhave never been adopted as a practical weapon.

SUMMARY OF THE INVENTION The present invention provides a hypervelocitygun which avoids the above-noted and other deficiencies of the existinghypervelocity guns. The major advantage of the present gun resides inits high firing rate and rapid reloading capabilities. In the regard,for example, it will become evident from the ensuing description thatthe present gun is uniquely adapted to automatic high rate firing.Generally speaking, the invention provides a hypervelocity guncharacterized by a primary breech mechanism located at the breech end ofa barrel for successively transporting primary rounds to firing positionand firing each round to effect forward propulsion of its projectilethrough the gun bore. Located at at least one booster station along thebarrel forwardly of its breech end is a secondary breech mechanism forsuccessively transporting projectileless booster rounds to firingposition. When in firing position, the propellant charge in each boosterround is disposed for ignition by the propellant gas generated by firingof a primary round upon forward travel of its projectile through therespective booster station. The propellant gas generated by each ignitedbooster round enters the gun bore and increases the propellant gaspressure directly behind the projectile to accelerate the latterforwardly through the bore.

As will appear from the later description, the present hypervelocity gunmay employ either closed chamber or open chamber breech mechanisms orboth closed and open chamber breech mechanisms in various combinations.That is to say, both the primary and secondary breech mechanisms mayembody a closed chamber breech action or an open chamber breech action,or one mechanism may embody a closed chamber action and the other anopen chamber action. In this regard, it should be noted that a closedchamber breech action is one in which each ammunition round is insertedor rammed axially into a circumferentially closed firing chamber throughone end of the chamber and the spent cartridge case of each fired roundis extracted axially from the chamber. Examples of this type of breechmechanism are the conventional belt or clip fed mechanisms, the revolvermechanism, the Gatling mechanism, and the separate chamber mechanism. Anopen chamber breech action, on the other hand, is one in which eachammunition round is introduced laterally into a firing chamber throughan open side of the chamber and the spent cartridge case of each firedround is ejected laterally through the open side of the chamber.Examples of such open chamber breech mechanisms are those disclosed inprior art Patents No. 2,983,223; 3,04l,938; 2,831,140; 2,847,784; and3,044,890. Moreover, a hypervelocity gun according of the invention mayhave either a fixed barrel or a rotary barrel construction. A fixedbarrel construction is one in which each gun barrel is stationary at alltimes and each firing chamber is stationarily aligned with the barrel,at least during firing of each ammunition round in the chamber. A rotarybarrel gun, on the other hand, is one in which the gun barrel or barrelsundergo continuous rotation about an axis parallel to and spacedlaterally from the barrel or barrels, and each firing chamber iscoaxially aligned with and undergoes rotation about the axis with abarrel during firing of each round in the chamber, thus to achieve avery high firing rate. The aforementioned Patent No. 3,041,939, forexample, describes a rotary barrel open chamber gun, and the remainingpatents listed disclose fixed barrel Open chamber guns. It will alsoappear that the primary and booster ammunition which is fired in an openchamber hypervelocity gun according to the invention may comprise fullycased open chamber ammunition having a cartridge case similar to thatdisclosed in the aforementioned prior art patents, semicombustibleammunition having a skeletonized cartridge case similar to thatdisclosed in the copending application entitled SemicombustibleAmmunition for Open Chamber Breech Mechanism, or caseless ammunitionsimilar to that disclosed in the copending application entitled SealedOpen Chamber Breech Mechanism and Caseless Ammunition Therefor.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a fixed barrel open chamberhypervelocity gun according to the invention;

FIG. 2 is an enlarged, fragmentary longitudinal section through the gun;

FIG. 3 is a section taken on line 3--3 in FIG. 2;

FIG. 4 is an enlargement of the area encircled by the arrow 4-4 in FIG.2;

FIG. 5 is a perspective view, partly broken away, of a boosterammunition round to be fired in the gun;

FIG. 5 is a perspective view, partly broken away, of a boosterammunition round to be fired in the gun;

FIG. 5a diagrammatically illustrates an electrical firing circuit andcylinder drive for the gun of FIGS. 14;

FIG. 6 is a longitudinal section through a modified hypervelocity gunaccording to the invention;

FIG. 7 is an enlarged section taken on line 77 in FIG. 6;

FIG. 8 is a perspective view, partly broken away, of a boosterammunition round to be fired in the hypervelocity gun of FIG 6;

FIG. 9 is a perspective view of a rotary barrel open chamberhypervelocity gun according to the invention; and

FIG. 10 is a longitudinal section through the gun of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general terms, the inventionprovides a hypervelocity gun, represented in FIGS. l-5 of the drawingsby the gun 10, having a barrel 12 containing a bore 1 4. Spaced alongthe barrel 12 are a number of breech mechanisms 16 and 18. Breechmechanism 16 is located at the breech end of the barrel and ishereinafter referred to as the primary breech mechanism. Breechmechanism 18, which is hereinafter referred to as a secondary breechmechanism is located at a booster station S spaced forwardly along thebarrel from the primary breech mechanism. As will appear from theensuing description, a hypervelocity gun according to the invention mayembody any number of booster stations and secondary breech mechanisms,depending upon the muzzle velocity to be obtained. For the sake ofsimplicity, the illustrated hypervelocity gun of the invention has beenshown to comprise a single secondary breech mechanism. As will appearpresently, the primary breech mechanism 16 operates to transport primaryammunition rounds in succession to firing position at the breech end ofthe barrel 12 and to fire each round in this position. The projectile ofeach fired round is propelled forwardly through the barrel by the highpressure propellant gas which is generated by the burning primarypropellant charge in the round. The secondary breech mechanism 18operates to transport secondary or booster ammunition rounds insuccession to firi g position at the booster station .8 in

such a way as to locate each boster round in firing positionsimultaneously with a primary round. Each booster round is aprojectileless round containing a booster propellant charge which, infiring position, is disposed to be ignited by the hot propellant gas ofthe respective fired primary round upon forward travel of its projectilethrough the booster station. The propellant gas generated by the boosterpropellant enters the barrel bore 14 behind the advancing projectile toaccelerate the latter through the bore.

It will be recalled that the present hypervelocity gun may employvarious types of primary and secondary breech mechanisms. Each of theillustrated breech mechanisms 1-6, 18 has a breech frame 20 supporting amovable ammunition carrier 26 containing at least one firing chamber 28.Carrier 26 is movable along a prescribed path of motion relative to itsbreech frame 20 to locate its firing chamber successively in anammunition infeed position, a firing position, and an injectionposition.

When in infeed position, the carrier 26 is disposed to receive anammunition round to be fired. When in firing position, the carrierfiring chamber 28 locates its contained ammunition round in firingrelation to the gun bore 14. Finally, when in ejecting position, thecarrier is disposed for ejection of the spent cartridge case of thefired round from the firing chamber after firing. Means 30 are providedfor driving the two carriers 26 of the breech mechanisms 16, 18 inunison to infeed, firing and ejection positions.

The primary breech mechanism 16 is designed to fire primary ammunitionrounds 32 including a projectile 34. The particular primary ammunitionillustrated is cased ammunication having a cartridge case 36 containingthe projectile 34, a primary propellant charge 38, and a primer 40.The'secondary breech mechanism 18 is designed to fire ammunition boosterrounds 42 including a booster propellant charge 44 only. The illustratedbooster rounds also comprise cased ammunition having a cartridge case 46containing the propellant 44.

Briefly, in operation of the present hypervelocity gun 10, the carriers26 of the breech mechanisms 16, 18 are first driven to infeed position.A primary ammunition round 32 is then introduced into the firing chamber28 of the primary breech mechanism 16 and a booster round 42 isintroduced into the firing chamber of the secondary breech mechanism 18.Thereafter, the carriers are driven to firing position and the firingmeans 48 of the primary breech mechanism is actuated to fire the primaryround in the latter mechanism. The firing chamber 28 of the primarybreech mechanism 16, when in firing position, is coaxially aligned withand opens forwardly to the gun bore 14. Accordingly, when the primaryround 32 is fired, its projectile 34 is propelled forward through thegun bore 14 by the propellant gas generated by the burning propellantcharge 38 in the round. The firing chamber of the secondary breechmechanism 18, when in firing position, opens to the gun bore 14 in sucha way that the propellant charge 44 in the booster round 42 containedwithin the chamber is exposed to and ignited by the hot propellant gasof the fired primary round upon forward travel of its projectile throughthe booster station S. The propellant gas generated by the fired boosterround then enters the gun bore 14 to increase the total propellant gaspressure behind the projectile and thereby accelerate the latterforwardly through the gun bore. At this point, it is significant torecall that while the illustrated hypervelocity gun of the invention hasa single secondary breech mechanism 18, a present gun may embody anynumber of secondary breech mechanisms spaced along the barrel 12. In theevent that a present gun is equipped with more than one secondary breechmechanism, the action of each additional secondary mechanism isidentical to that described above. Accordingly, the propellant gaspressure behind the projectile of a fired primary round is increased anumber of times as the projectile t avels forwardly through the bore andexposes the booster rounds in the successive secondary breech mechanismsto the hot propellant gas of the primary round.

In the particular hypervelocity gun of the invention under discussion,the primary and secondary breech carriers 26 are cylinders which containthe firing chambers 28. These cylinders are rotatably mounted withinchambers 22 in the primary and secondary breech frames 20, respectively,for turning on axis 24, parallel to and spaced laterally from the barrel12. The carrier drive means 30 drives the cylinders in rotation inunison to locate the primary and secondary firing chambers in theirinfeed, firing, and ejection positions.

Referring now in more detail to the hypervelocity gun 10 of theinvention which has been selected for illustrati n in FIGS. l5 ofthe'drawings, it will be seen that the" breech frames of the primary andsecondary breech mechanisms 16, 18 are rigidly joined to one another bytop and bottom connecting straps 48, 50 to form a rigid breechstructure. At the front end of this breech structure is a trunnionsupport or boss 52. A trunnion 54 extends through this boss, laterallyof the gun, and projects a distance beyond opposite sides of the boss.The projecting ends of the trunnion 54 are rotatably received inbearings 56 fixed within the upstanding arms 58 of a gun carriagebracket 60. The gun is thus pivotally supported for training of the gunin elevation. The bracket 60, in turn, may be pivotally supported fortraining of the gun in azimuth. It is obvious, of course, that the gunmay be supported in a fixed mount, if desired.

As noted earlier, a hypervelocity gun according to the invention mayutilize either or both an open chamber breech action and a closedchamber breech action. The particular gun under discussion is an openchamber gun which employs an open chamber breech action in both itsprimary and secondary breech mechanisms 16, 18. In this regard, it willbe observed that each breech mechanism is essentially a conventionalopen chamber breech mechanism of the type disclosed in theaforementioned prior art patents. Thus, the breech frame 20 of eachbreech mechanism has the characteristic, generally fiat rectangularshape and contains a generally rectangular central opening which openslaterally through opposite sides of the frame to form the chamber 22. Asis wellknown to those versed in the open chamber gun art, the cylinderof an open chamber breech mechanism may contain one or more firingchambers and may be driven in unidirectional rotation or in oscillation.Each breech cylinder 26 of the illustrated open chamber hypervelocitygun 10 of the invention contains a number of uniformly spaced firingchambers 28 and is driven in unidirectional rotation to locate eachfiring chamber in its infeed, firing, and ejection position. Inaccordance with a characteristic feature of open chamber mechanisms,each firing chamber 28 opens laterally through the circumference andlongitudinally through the front and rear ends of its respectivecylinder. The open sides of each chamber 22 define ammunition infeed andejection openings with which each firing chamber of the contained breechcylinder 26 registers when in infeed and ejection positions,respectively. When in firing position, the open side of each firingchamber is closed by the firing strap 62 of the corresponding breechframe.

A further characteristic feature of open chamber breech mechanismsresides in the complementary, generally triangular shapes of the openfiring chambers and ammunition in transverse cross-section. In thisregard, it will be observed that the firing chambers 28 of theillustrated open chamber gun 10 and the ammunition rounds 32, 42 whichare fired in the gun have the same generally triangular round shape intransverse cross-section as the firing chambers and ammunition disclosedin the aforementioned prior art patents. The side walls of each firingchamber and the sides of each ammunition round are cylindrically curvedto the same radius of curvature as the breech cylinders 26.

When an ammunition round is positioned in a firing chamber of eitherbreech mechanism 16 or 18, two sides of the round seat flush against theside walls of the chamber and the third, exposed side of the round isfiush with the cylinder circumference. The inner surface of the firingstrap 62 of each breech frame 20 is also cylindrically curved to thesame radius as and slidably engages the circumference of its containedcylinder 26.

In the particular open chamber gun under discussion, the barrel means 12Comprises front and rear barrel sections 12a and 12b, respectively.Front barrel section 12a is secured at its rear end to and extendsforwardly from the front end of the secondary breech frame 20. The rearbarrel section 12b extends between and is secured at its ends to thefront end of the primary breech frame and the rearend'of the secondarybreech frame. These barrel" 7 sections are coaxially disposed in spacedparallel relation to the common axis 24 of the breech cylinders 26.

It will be recalled that the illustrated open chamber hypervelocity gun10 is equipped with drive means 30 for driving the primary and secondarybreech cylinders 26 to sequentially locate each of their respectivefiring chambers 28 in infeed, firing, and ejection positions. Theillustrated drive means comprise a connecting drive shaft 64 whichextends between the cylinders along their common axis 24 of rotation.The rear end of this shaft extends rotatably through the forward end ofthe primary breech frame 20 and is coaxially secured to the forward endof the primary breech cylinder 26. The forward end of the shaft extendsrotatably through the rear end of the secondary breech frame and iscoaxially secured to the rear end of the secondary breech cylinder.Accordingly, the connecting shaft joins the cylinders for rotationthereof in unison. Shaft 64 extends through the cylinders to rotatablysupport the latter on their respective breech frames. It is significantto note here that the cylinders are so oriented on their common axis 24that their firing chambers are axially aligned. The coresponding firingchambers of the two cylinders thus rotate in unison to their infeed,firing, and ejection positions.

The illustrated cylinder drive means 30 further comprise an electricdrive motor 66, the shaft of which is drivably coupled to the rear endof the cylinder shaft 64 through in intermittent rotary drive mechanism68 (FIG. 5a). The particular drive mechanism illustrated is at Genevadrive having an input member 70 coupled to the motor shaft and an outputmember 72 coupled to the cylinder shaft. This Geneva drive is soconstructed and arranged as to drive the breech cylinders 26 inintermittent rotation in such a way that the cylinder firing chambers 28are momentarily arrested in their firing positions. As noted earlier,the primary ammunition rounds 32 are fired in firing position by theprimary breech firing means 48. This firing means is an electricalfiring means actuated by a firing switch 74. Referring to FIG. 5a, itwill be seen that the firing switch 74 is operated by a rotary cam 76which is coupled to the input member 70 of the Geneva drive 68. This camis oriented to close the firing switch and thereby energize theelectrical firing means 48 during that portion of each revolution of theinput member in which the breech cylinders 26 are retained stationary infiring position by the output member 72 of the Geneva drive. Thecylinder drive motor 66 may be controlled by a trigger switch 78operated by a trigger mechanism (not shown) to permit selective firingof the gun.

It is now evident that when the trigger switch 78 is closed, the breechcylinders 26 are driven in intermittent rotation in such a way that thecylinder firing chambers 28 rotate in succession through their infeed,firing, and ejection positions. Indicated at 80 in the drawings areammunition infeed means for feeding primary ammunition rounds 32laterally in succession to the primary breech firing chambers andfeeding booster ammunition rounds 42 laterally in succession to thesecondary breech firing chambers upon rotation of these chambers toinfeed position. It will be obvious to those versed in the art thatvarious ammunition infeed means may be employed in the gun. Theparticular infeed means shown comprise ammunition hoppers which feedtheir respective rounds to their corresponding cylinders through theamunition infeed openings in the breech frames 20. These hoppers may beequipped with spring loaded followers or the like for urging the roundstoward the cylinders. After entrance of each pair of the ammunitionrounds 32, 42 into aligned primary and secondary firing chambers 28, therounds rotate with the chambers to firing position. In the hypervelocitygun 10 under discussion, both the primary and secondary firing chambers,when in firing position, are coaxially aligned with the gun bore 14.Thus, each primary firing chamber, when in firing position, is coaxiallyaligned with and opens forwardly to the breech end of the bore. Eachsecondary firing chamber, when in firing position, is coaxially disposedbetween the front and rear barrel sections 12a, 12b and opens forwardlyto the bore in the front barrel section and rearwardly to the bore inthe rear barrel section.

The primary ammunition rounds 32 are identical to those disclosed in theaforementioned prior art patents. Accordingly, there is no need todescribe these rounds in any greater details than presented earlier. Theconstruction of the booster ammunition rounds 42, however, is novel andconstitutes an important feature of the invention. One of these roundsis shown in detail in FIG. 5. Each illustrated booster round has anouter yieldable noncombustible cartridge case 46. This cartridge case,and that of each primary round, have a generally triangular round shapein cross-section and are sized to complement and seal their respectiveprimary and secondary breech cylinder firing chambers against propellantgas leakage during firing, in the same manner as explained in theearlier listed patents. Extending centrally through the cartridge case46 of each booster round 42 is a perforated tube 86. The ends of thistube are sealed to the end walls of the cartridge case 46. As explainedbelow, the tube 86 of each booster round 42, when in firing position,forms a section of the gun bore 14 and serves to guide the projectile 34of a fired primary round 32 during its travel through the boosterstation 5. To this end, the internal diameter of the tube is the same asthat of the gun bore 14, proper, and the tube is made of non-combustiblematerial suitable to its projectile guiding function. The interior spaceof each booster round 42, between the outer cartridge case 46 and innertube 86 of the round, is filled with the booster propellant 44. Acombustible cover sleeve 88 may be disposed about the tube 86,particularly if the booster propellant 44 is a loose grain propellant,to shield the propellant and prevent its loss through the tube portsduring handling and infeed.

The operation of the illustrated open chamber hypervelocity gun 10 willnow be explained. The gun is initially conditioned for firing by fillingthe ammunition infeed means or hoppers 80 of the primary and secondarybreech mechanisms 16, 18 with primary and booster ammunition rounds 32,42, respectively.

The trigger switch 78 is then closed to energize the breech cylinderdrive motor 66 and thereby effect driving of the primary and secondarybreech cylinders is intermittent rotary motion through their respectiveinfeed, firing, and ejection positions. As each pair of correspondingprimary and secondary firing chambers 28 rotate to infeed position, aprimary round 32 is fed laterally into the primary chamber and a boosterround 42 is fed laterally into the secondary chamber from the ammunitionhoppers 80 and through the infeed openings in the breech frames 20 andthe open sides of the firing chambers. Thereafter, the rounds arerotated to firing position in their respective breech mechanisms 16, 18and the primary round is electrically fired in the primary breech mechnism by closure of the cam actuated firing switch 74. Each booster round42, when in firing position, is located with its inner perforated tube86 in coaxial alignment with the gun bore 14, so as to effectively forma section of the bore, as shown in the drawings.

When each primary ammunition round 32 is fired in firing position, inthe manner just explained, its projectile 34 is propelled forwardlythrough the gun bore 14 by the propellant gas pressure generated by thefired primary round. During its forward travel through the gun bore, theprojectile passes through and uncovers the ports in the centralperforated tube 86 of the booster round 42 currently in firing positionwithin the secondary breech mechanism 18. The booster propellant 44 inthe booster round is thereby exposed to an ignited by the hot propellantgas of the fired primary round. In this regard, attention is directed tothe fact that the combustible sleeve 88 in the booster round servesmerely to prevent escape of the booster propellant through the tubeports during storage and handling of the round, and is consumed by thehot propellant gas of the fired primary round to permit exposure of thebooster propellant to the gas as just explained. The propellant gasgenerated by the burning booster propellant then enters the gun bore toincreased the propellant gas pressure in the bore behind the advancingprojectile of the fired primary round 32 and thereby accelerate theprojectile to the desired hyper-muzzle velocity. At this point, it issignificant to recall that a hypervelocity gun according to theinvention may be provided with any number of booster stages. It will beunderstood that the booster propellants of the successive booster stagesare ignited in essentially the same way as described above in connectionwith the illustrated gun 10 upon forward travel of the projectile of thefired primary round through the successive booster stages.

During firing of the gun 10, the cartridge cases 38 and 46 of the firedprimary and booster rounds 32, 42, are expanded by propellant gaspressure outwardly against the walls of their respective firing chambers28 and breech frames 20 to seal the breech interfaces against propellantgas leakage, in the manner explained in the aforementioned prior artpatents. After firing, the firing chambers 28 currently in firingposition are rotated to ejection position to eject the spent cartridgecases of the fired primary and booster rounds, and a pair of liveprimary and booster rounds are rotated to and fired in firing position.This firing action continues as long as the breech cylinder drive motor66 remains energized and the ammunition hoppers contain primary andbooster ammunition rounds.

Turning now to FIGS. 6 through 8, there is illustrated a modifiedhypervelocity gun according to the invention having a primary breechmechanism 102 which utilizes a closed chamber breech action and asecondary breech mechanism 104 which utilizes an open chamber breechaction. In the interest of simplicity of description and illustration,only the breech means and barrel of the modified gun have been shown andwill be described. It will be understood, of course, that the actual gunwill be provided with cylinder drive means, and ammunition infeed meansfor each breech mechanism. In this regard, it should be noted that theopen chamber breech mechanism may have a hopper feed like that justdescribed. The closed chamber primary breech mechanism may be equippedwith any conventional ammunition infeed means suitable for use with theillustrated mechanism.

The primary breech mechanism 102 has a breech frame 106 containing abreech chamber 108 in which is rotatable mounted a revolver cylinder110. Extending through the cylinder 110, parallel to its rotation axis112, are a number of laterally closed firing chambers 114. These firingchambers are uniformly spaced about the axis of and open through thefront and rear ends of the cylinder 110. Each firing chamber isconventionally shaped and dimensioned to receive a standard ammunitioncartridge 116, hereinafter referred to as a primary round. Breechchamber 108 opens through opposite sides of the breech frame 106.Secured at its rear end to an extending forwardly from the front end ofthe breech frame 106 in spaced and parallel relation to the cylinderaxis 112 is a barrel 118 containing a bore 120.

Revolver or cylinder 110 is rotatable in the breech chamber 108 tolocate each of its firing chambers 114 in ammunition infeed, firing, andcartridge case ejection positions. Each firing chamber, when in infeedposition, is exposed through one open side of the breech chamber topermit axial insertion of a primary cartridge or round 116 into thechamber. When in firing position, each firing chamber is coaxiallyaligned with and opens forwardly to the gun bore 120 to condition aprimary round to be fired in the chamber. Each firing chamber, when inejection position, is exposed through one open side of the breechchamber to permit axial extraction of a spent cartridge case from thechamber after firing. Secured to and extending coaxially from thecylinder 110 and rotatably through the rear end of the breech frame 106is a shaft 122 by which the cylinder may be rotated to sequentiallylocate each of its firing chambers in infeed, firing, and ejectionpositions. Mounted in the rear end of the breech frame 106, on the axisof the gun bore 120, is a firing pin 124.

The secondary breech mechanism has a breech frame 126 containing a bore128 receiving the barrel 118. The secondary breech frame is rigidlysecured to the barrel in any convenient way and is sealed to the barrel.Breech frame 126 contains a chamber .132 which is laterally offset fromthe frame bore 128. Rotatably mounted within the chamber 132, forturning on an axis 134 parallel to and spaced from the axis of the gunbore 120, is an open chamber carrier or cylinder 136. Cylinder 136contains a number of uniformly spaced longitudinal firing chambers 138which open laterally through the circumference of the cylinder. Each ofthese firing chambers has the same generally triangular round shape intransverse crosssection as the firing chambers in the earlier describedhypervelocity gun of the invention. Breech chamber 132 opens throughopposite sides of the secondary breech frame 126 to define ammunitioninfeed and ejection openings. Breech frames 106, 126 are rigidly joinedby connecting plates 139, 193a.

The secondary breech cylinder 136 is rotatable to locate each of itsfiring chambers 138 in ammunition infeed, firing, and ejectionpositions. Each firing chamber, when in infeed position, opens laterallythrough one open side of the chamber 132 to permit lateral infeedmovement of a booster ammunition round 140 into the chamber. When infiring position, each firing chamber is closed by the secondary breechframe 126 to permit firing of the booster round in the chamber. When inejection position, each firing chamber opens laterally through one openside of chamber 132 to permit lateral ejection of the spent cartridgecase of a fired booster round from the chamber. Extending through thewall of the barrel 118 and the secondary breech frame 126 are a numberof propellant gas ports 142 which communicate each firing chamber 138,when in firing position, to the gun bore 120.

As in the earlier hypervelocity gun 10 of the invention, the breechcylinders 110, 136 of the modified hypervelocity gun 100 are drivablycoupled for unified rotation of the firing chambers 114, 138 to firingposition. To this end, the shaft 122 of the primary breech cylinder 110extends forwardly from the cylinder and rotatably through the front endof the primary breech frame 106. Fixed to the forward end of this shaftis a gear 144. Fixed to and extending coaxially from the secondarybreech cylinder 136 and rotatably through the rear end of the secondarybreech frame 126 is a shaft 146. A gear 148 fixed on the end of theshaft 146 meshes with the gear 144 to drivably couple the primary andsecondary breech cylinders 110, 136.

It is significant to note at this point that in the earlier describedgun 10 of the invention, the primary and secondary breech cylinders arerequired to contain the same number of firing chambers. This resultsfrom the fact that the cylinders are directly connected to the sameinterconnecting shaft. In the modified gun under discussion, on theother hand, the primary and secondary cylinders may contain the samenumber or a different number of firing chambers. In the event that thecylinders contain the same number of firing chambers, the cylinder drivegears 144, 148 will mesh in a l to 1 ratio. On the other hand, if thenumber of firing chambers in the cylinders differ, the gears 144, 148will mesh in other than a 1 to 1 ratio depending upon the particularnumber of firing chambers in each cylinder. In any event, the ratio ofthe gears is such as to effect rotation of each secondary firing chamber138 to firing position simultaneously with rotation of each primaryfiring chamber 114 to firing position. It is obvious, of course, thatthe primary and secondary breech cylinders 110, 136 of the modified gun100, unlike the breech cylinders of the earlier described gun 10, rotatein opposite directions.

As already noted, the primary ammunition cartridges or rounds 116 whichare fired in the primary breech mechanism 102 are conventional.Accordingly, these primary rounds need not be described in detail.Suffice it to say that each primary round comprises a generallycylindrical metallic cartridge case 116a containing a primary propellantcharge (not shown) and a projectile 116b which is secured to and extendsforwardly from the front end of the cartridge case. The primary firingchambers 114 are shaped to complement the cartridge case 116a, as shown.

The booster ammunition rounds 140 which are fired in secondary breechmechanism 126 comprise a yieldable, non-combustible cartridge case 140awhich is shaped to complement the secondary firing chambers 138.Contained within the cartridge case is a booster propellant charge 14%.Formed in at least the side of the cartridge case which is exposed whenthe booster round is positioned in a secondary firing chamber 138 is anopening 1400 closed by a combustible cover sheet 140d.

As in the previous embodiment of the invention, the sides of each firingchamber and the inner wall of the breech frame firing strap of thesecondary breech mechanism 104, as well as the sides of the boosterrounds 140, are cylindrically curved to the same radius as thecircumference of the secondary breech cylinder 136. Moreover, when abooster round is positioned in a firing chamber 138, the exposed,apertured side of the round is flush with the cylinder circumference.

The modified hypervelocity gun 100 is conditioned for firing by rotatingthe primary and secondary breech cylinders 110, 136 to locate firingchambers 114, 138 of the respective cylinders in infeed position.Primary and booster rounds 116, 140 are then inserted into therespective firing chambers, after which the cylinders are rotated tolocate these rounds in firing position. At this point, the firing pin124 is actuated to fire the primary round. The projectile 116b of thefired primary round is thereby propelled forwardly through the gun boreby propellant gas pressure. During its forward travel through the gunbore, the projectile uncovers the propellant gas ports 142 in the wallof the barrel 118. The booster round currently in firing position withinthe secondary breech mechanism 104 is thereby exposed to the hotpropellant gas generated by the fired primary round. As in the previousembodiment of the invention, the hot propellant gas consumes thecombustible cover sheet 140d and ignites the booster propellant charge140b in the round. The propellant gas then generated by the boosterpropellant enters the gun bore 120 through the ports 142 to increase thepropellant gas pressure behind the advancing projectile 116/5 of thefired primary round and thereby accelerate the projectile to the desiredmuzzle velocity. It will be understood that the modified hypervelocitygun 100, like the earlier described gun 10 of the invention, may beprovided with as many booster firing stations along the barrel 118 asnecessary to accelerate the projectile to the desired muzzle velocity.After firing, the primary and secondary firing chambers 114, 138currently in firing position are rotated to ejection position to permitejection of the spent cartridge cases of the fired rounds from thechamber.

Each of the hypervelocity guns of the invention described thus far arefixed barrel guns in which the gun barrel remains stationary at alltimes and the primary and secondary firing chambers are retainedstationary in firing position relative to the barrel during firing ofeach pair of primary and booster ammunition rounds in the chambers. Asnoted earlier, however, a hypervelocity gun according to the inventionmay embody a rotary barrel construction. FIGS. 9 and 10 illustrate sucha rotary barrel hypervelocity gun 200. Gun 200 has a primary breechmechanism 202 and a secondary breech mechanism 203 each including abreech frame 204. Breech frames 204 are rigidly joined by top and bottomconnecting straps 206. Each frame has a central portion 208 withgenerally fiat parallel sides and flange-like bearing rings 210 at theends of the frame. The several bearing rings on the two breech frameshave a common axis located in the plane of the connecting straps andextending parallel to the straps, approximately midway therebetween.Within each breech frame 204 is a chamber 212 which opens longitudinallythrough the front and rear ends of the frame and laterally throughopposite sides of the central frame portion to form ammunition infeedand ejection openings, as in the gun of FIG. 1. The rear end of the topconnecting strap 206 provides the firing strap for the primary breechframe 204, and the front end of this strap provides a firing strap forthe secondary breech frame 204.

Rotatable within each breech frame 204, on the common axis of the breechframe bearingrings 210, is a carrier or cylinder 214. The ends of eachcylinder are exposed through the open ends of its respective chamber212. Each cylinder is rotatably supported in its respective breech frame204 by bearing units 216 which surround the ends of the cylinder in theplanes of the corresponding breech frame bearings rings 210.

Within each cylinder 214 is at least one firing chamber 218. In thisinstance, each cylinder contains a number of uniformly spaced firingchambers. These firing chambers have the same generally triangular roundshape in transverse cross-section as those in the gun of FIG. 1. Eachchamber opens laterally through the circumference of its respectivecylinder 214, in the region between the bearing rings 210 of thecorresponding breech frame 204. The ends of the firing chambersterminate short of the cylinder ends and are closed by front and rearend walls 222, 224 on the cylinders.

The rotary barrel gun 200 has a barrel 226 for each firing chamber 218.The several barrels 226 parallel the rotation axis of the breechcylinders 214 and are coaxially aligned with the respective firingchambers. Each barrel has a front section 22611 and a rear section 22Gb.Each front barrel section 226a extends forwardly from the front end ofthe secondary breech cylinder 214 and is threaded or otherwise securedin the front wall 222 of its respective secondary firing chamber. Eachrear barrel section 22617 extends between the primary and secondarybreech cylinders 214 and is secured in the front wall 222 of itsrespective primary firing chamber and in the rear wall 224 of itsrespective secondary firing chamber. The bores 228 in the barrels arecoaxially aligned with and open longitudinally to the firing chambers,as shown. Fixed to the muzzle ends of the barrels is a collar 230 forrestraining the barrels against relative lateral deflection.

It is evident at this point that the primary and secondary breechcylinders 214 are connected by the rear barrel sections 2261) forrotation of the cylinders in unison to locate their firing chambers 218in ammunition infeed, firing, and ejection positions in much the sameway described earlier in connection with the gun of FIG. 1.

When in infeed position, the open sides of the corresponding primary andsecondary firing chambers register with the ammunition infeed openingsin the primary and secondary breech frames, respectively, to permitlateral infeed movement of primary and booster ammunition rounds intothe chambers from ammunition infeed means 234. In this instance, as inthe gun of FIG. 1, the ammunition infeed means 234 comprise ammunitionhoppers. When in firing position, the open sides of the correspondingprimary and secondary firing chambers 218 are closed by the breech framefiring straps to condition the gun for firing the primary and boosterammunition rounds. When in ejection position, the open sides of thecorresponding primary and secondary firing chambers register with theejection openings in the primary and secondary breech frames 204 topermit lateral ejection of the spent cartridge cases of the fired roundsfrom the chambers. Unlike the gun of FIG. 1, however, the breechcylinders 214 in the rotary barrel gun 200 are driven continuously inrotation, even during firing, by a motor 232 at the breech end of theprimary breech frame 204. Also unlike the gun of FIG. 1, the barrels 226in the gun 200 rotate with the cylinders.

The rotary barrel gun 200 fires primary open chamber ammunition rounds236 which, like the primary rounds 32 fired in the gun of FIG. 1, havean electrical primer. The gun 200 fires booster ammunition rounds 238which are identical to the booster rounds 42 which are fired in the gunof FIG. 1. Gun 200 has an electrical firing means 240' for firing eachprimary round in firing position.

The rotary barrel hypervelocity gun 200' of the invention operates inmuch the same way as the fixed barrel gun of FIG. 1. Thus, duringunified rotation of the primary and secondary breech cylinders 214 ofthe gun 200 by the cylinder drive motor 232, the primary and secondaryfiring chambers 218 rotate in succession through their infeed, firing,and ejection positions. As the corresponding firing chambers rotatethrough infeed position, they receive primary and booster ammunitionrounds 236, 238, respectively, from the ammunition infeed means 234.During subsequent rotation of the chambers through firing position, theprimary round is fired by the electrical firing means 240. Theprojectile of the round is thereby propelled forwardly through thecorresponding gun bore 228 by the high pressure propellant gas generatedin the fired round. The booster propellant charge in the boosterammunition round 238 currently in firing position in the secondarybreech mechanism 203 is ignited by this hot propellant gas, in the samemanner as explained earlier in connection with FIG. 1, as the advancingprojectile travels forwardly though the secondary mechanism. The highpressure propellant gas generated by the booster propellant then entersthe corresponding gun bore 228 behind the advancing projectile toaccelerate the latter through the bore. The spent cartridge cases of thefired primary and booster rounds 236, 238 are ejected from the firedchambers during subsequent rotation of the chambers through ejectionposition. This same firing action or cycle is repeated for each pair ofcorresponding primary and secondary firing chambers 218 duringcontinuous firing operation of the gun.

It is now evident, therefore, that the rotary barrel hypervelocity gun200, just described, operates in much the same way as the fixed barrelhypervelocity gun of FIG. 1. The major difference between the two guns,of course, resides in the fact that the primary and secondary breechcylinders 214 and the gun barrels 226 of the gun 200 undergo continuousrotation, even during firing. The primary advantage of this rotarybarrel gun construction is its extremely high firing rate. Accordingly,the gun 200- is characterized by both hyper-muzzle velocity andextremely high firing rate.

At this point, it is significant to recall that While the invention hasbeen disclosed in connection with hypervelocity guns having certainspecific primary and secondary breech mechanisms, other types of breechmechanisms, such as those referred to earlier, may be employed in theinvention. Moreover, a present hypervelocity gun may employ othercylinder drive means, firing means, and ammunition infed means thanthose shown.

It should also be noted that while the invention has beendisclosed inconnection with the firing of cased primary and booster ammunition, thepresent hypervelocity gun may fire uncased ammunition. In this regard,attention is directed to the earlier mentioned copending applicationentitled Sealed Open Chamber Breech Mechanism and Caseless AmmunitionTherefor, which discloses uncased open chambertarnmunition which may befired in the primary breech mechanism of the gun. ,The uncased boosterammunition to be fired in the present gun will be like that illustratedin the present drawings, except that the outer cartridge case will beeliminated and replaced by an additional quantity of molded boosterpropellant. When firing uncased ammunition of this type, of course, theprimary and secondary breech mechanisms of the gun will be equipped withsuitable obturator means, such as those disclosed in the application,for sealing the breech interfaces against propellant gas leakage. Inaddition, semicombustible open chamber ammunition of the type disclosedin the aforementioned copending application entitledsemicombustibleAmmunition for Open Chamber Breech Mechanism may be firedin the present gun.

While the invention has been disclosed in connection with certain of itsphysical embodiments, it will be understood that various modificationsof the invention are possible within the spirit and scope of thefollowing claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A hypervelocity gun for firing individual elongate fixed chargeprimary ammunition rounds of fixed size and shape each containing aprimary propellant and a projectile and individual elongate fixed chargebooster ammunition rounds of fixed size and shape and containing abooster propellant, comprising:

a barrel having a bore;

a primary breech mechanism at the breech end of said barrel including abreech frame member, a primary ammunition carrier member having aprimary firing chamber for receiving said primary ammunition rounds insuccession, means supporting said carrier member on said frame memberfor movement of said firing chamber with said carrier member along aprescribed path of motion and through an ammunition infeed positionwherein said firing chamber is disposed to receive a primary ammunitionround to be fired, a primary firing position wherein said firing chamberlocates its contained primary round in firing relation to the breech endof said bore to permit firing of the contained round in said firingchamber, and an ejection position;

a secondary breech mechanism along said barrel at a booster stationforwardly of said primary breech mechanism including a secondary breechframe member, a secondary ammunition carrier member containing at leastone secondary firing chamber for receiving said booster ammunitionrounds in succession, means supporting said secondary carrier member onsaid secondary frame member for movement of said secondary firingchamber with said secondary carrier member along a prescribed path ofmotion and through an ammunition infeed position wherein said secondaryfiring chamber is disposed to receive a booster ammunition round to befired, a firing position wherein said secondary firing chamber locatesthe booster propellant of its contained booster round in ignitionrelation to said bore, and an ejection position; and

means for driving said carrier members in timed relation to locate abooster ammunition round in secondary firing position concurrently withlocation of each primary ammunition round in primary firing position,whereby when a primary ammunition round is fired in primary firingposition, the projectile of the fired primary round is propelledforwardly through said bore by the high pressure propellant gasgenerated by the fired primary round, and the booster propellant of thebooster round in secondary firing position is ignited by said propellantgas upon forward travel of the advancing projectile through said boosterstation, thereby to generate additional high pressure propellant gaswhich enters said bore behind the advancing projectile for acceleratingthe latter through said bore.

2. A hypervelocity gun according to claim 1,wherein:

said carrier driving means comprise means for driving said carriermembers in timed relation to said infeed, firing, and ejectionpositions.

3. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primarybreech mechanism;

each of said breech mechanisms including a breech frame containing achamber and an ammunition infeed opening to said chamber, and anammunition carrier supported on said frame within said chamber forrotation on an axis parallel to and laterally spaced from said bore;

the carrier of said primary breech mechanism containing a primary firingchamber and being rotatable to locate said primary firing chamber in anammunition infeed position wherein said primary firing chamber registerswith the infeed opening in the primary breech frame, and a firingposition wherein said primary firing chamber is coaxially aligned withand opens forwardly to the breech end of said bore;

the carrier of said secondary breech mechansm containing a secondaryfiring chamber and being rotatable to locate said secondary firingchamber in an ammunition infeed position wherein said secondary firingchamber registers with the infeed opening in the secondary breech frame,and a firing position wherein said secondary firing chamber is coaxiallyaligned with and opens forwardly and rearwardly to said gun bore; and

means for driving said carriers in rotation to simultaneously locatesaid primary and secondary firing chambers in their respective firingpositions.

4. A hypervelocity gun according to claim 3, wherein:

said barrel is secured to and remains stationary with the frames of saidbreech mechanisms; and

said carriers are driven in intermittent rotation in such a way thatsaid firing chambers are momentarily arrested in firing position.

5. A hypervelocity gun according to claim 3, wherein:

said barrel is secured to said carriers in coaxial alignment with saidfiring chambers and rotates with said carriers; and

said barrel and carriers are driven in continuous rotation.

6. A hypervelocity gun, according to claim 3, wherein:

at least one of said breech mechanisms comprises an open chamber breechmechanism; and

the firing chamber of said open chamber breech mechanism opens laterallythrough the circumference of the respective carrier.

7. A hypervelocity gun according to claim 3, wherein:

one of said breech mechanisms comprises a closed chamber breechmechanism; and

said firing chamber of said colsed chamber mechanism is closed about itsentire circumference and opens axially through one end of the respectivecarrier.

8. An open chamber hypervelocity gun comprising:

a barrel containing a bore;

a primary open chamber breech mechanism at the breech end of saidbarrel;

a secondary open chamber breech mechanism along said barrel forwardly ofsaid primary breech mechanrsm;

each of said breech mechanism including a breech frame containing achamber and a lateral ammunition infeed opening to said chamber, and anopen chamber cylinder supported on said frame within said chamber forrotation on an axis parallel to and laterally spaced from said bore;

the cylinder of said primary breech mechanism containing a primaryfiring chamber opening laterally through the circumference andlongitudinally through the front end of the primary cylinder and beingrotatable to locate said primary firing chamber in an ammunition infeedposition wherein the open side of said primary firing chamber registerswith the infeed opening in the primary breech frame, and a firingposition wherein the open side of said primary firing chamber is closedby the primary breech frame and the primary firing chamber opensforwardly to the breech end of said bore;

the cylinder of said secondary breech mechanism containing a secondaryfiring chamber opening laterally through the circumference andlongitudinally through the front and rear ends of the secondary cylinderand being rotatable to locate said secondary firing chamber in anammunition infeed position wherein the open side of said secondaryfiring chamber registers with the infeed opening in the secondary frameand a firing position wherein the open side of said secondary firingchamber is closed by the secondary breech frame and said secondaryfiring chamber is coaxially aligned with and opens forwardly andrearwardly to said gun bore;

means for driving one cylinder in rotation to locate the correspondingfiring chamber in infeed and firing position; and

means drivably coupling said primary and secondary cylinders forrotation of said cylinders in unison to simultaneously locate saidprimary and secondary firing chambers in their respective infeed andfiring positions.

9. An open chamber gun according to claim 8, wheresaid cylinders have acommon axis of rotation; and

said coupling means comprise a shaft extending between and coaxiallysecured to said cylinders.

10. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primarybreech mechanism;

each of said breech mechanisms including a breech frame containing abreech chamber and an ammunition infeed opening to said chamber, and anammunition carrier supported on said frame within said chamber forrotation on an axis parallel to and laterally spaced from said bore;

the carrier of said primary breech mechanism containing a primary firingchamber and being rotatable to locate said primary firing chamber in anammunition infeed position wherein said primary firing chamber registerswith the infeed opening in the primary breech frame, and a firingposition wherein said primary firing chamber is coaxially aligned withand opens forwardly to the breech end of said bore;

the carrier of said secondary breech mechanism containing a secondaryfiring chamber and being rotatable to locate said secondary firingchamber in an ammunition infeed position wherein said secondary firingchamber registers with the infeed opening in the secondary breech frame,and a firing position wherein said secondary firing chamber communicateslaterally with said bore through ports in the wall of said bore; and

means for driving said carriers in rotation to simultaneously locatesaid firing chambers in their respective firing positions.

11. An open chamber gun according to claim 10,

wherein:

said carriers rotate on spaced parallel axes; and

said coupling means comprise meshing gears secured to said carriers,respectively.

12. An open chamber gun according to claim 10,

wherein 13. A hypervelocity gun according to claim 12, wheresaid primarybreech mechanism comprises a closed chamber breech mechanism wherein thecorresponding carrier is a revolver cylinder and the correspondingfiring is circular in cross-section in planes normal to the axis of saidcylinder and opens through the ends of said cylinder.

14. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primarybreech mechanism;

each of said breech mechanisms including a breech frame containing achamber and an ammunition infeed opening to said chamber, and a cylindersupported on said frame within said chamber for rotation on an axisparallel to and laterally spaced from said bore;

the cylinder of .said primary breech mechanism containing a number ofuniformly spaced primary firing chambers and being rotatable to locateeach primary firing chamber in an ammunition infeed position wherein therespective primary firing chamber registers with the infeed opening inthe primary breech frame, and a firing position wherein the respectiveprimary firing chamberis coaxially aligned with and opens forwardly tothe breech end of said bore; and

the cylinder of said secondary breech mechanism containing a number ofuniformly spaced secondary firing chambers and being rotatable to locateeach secondary firing chamber in an ammunition infeed position whereinthe respective secondary firing chamber registers with the infeedopening in the secondary breech frame, and a firing position wherein therespective secondary firing chamber opens to said bore.

15. A hypervelocity gun according to claim 14, whereat least one of saidbreech mechanisms comprises an open chamber breech mechanism; and thefiring chambers of said open chamber breech 1 7 mechanism open laterallythrough the circumference of the corresponding cylinder.

16. A hypervelocity gun according to claim 14, whereeach of said breechmechanisms comprises an open chamber breech mechanism; and

the firing chambers of each breech mechanism open laterally through thecircumference of the corresponding cylinder.

17. A hypervelocity gun according to claim 14, whereone of said breechmechanisms comprises a closed chamber breech mechanism; and

the cylinder of said closed chamber breech mechanism comprises arevolver cylinder, the firing chambers of said closed chamber breechmechanism are circular in cross-section in planes normal to the cylinderaxis and open through the ends of said revolver cylinder.

18. In combination:

a hypervelocity gun including a barrel containing a bore, a primarybreech mechanism at the breech end of said barrel including a primaryfiring chamber, located in a primary firing position wherein saidchamber is coaxially aligned with and opens forwardly to said bore, anda secondary breech mechanism along said barrel at a booster stationforwardly of said primary breech mechanism including a secondary firingchamber located in a secondary firing position wherein said secondarychamber is coaxially aligned with and opens forwardly and rearwardly tosaid bore;

a primary ammunition round within said primary firing chamber includinga projectile and a primary propellant adapted to be ignited to generatea high pressure propellant gas for propelling said projectile forwardlythrough said bore;

a unitary fixed charge booster ammunition round within said secondaryfiring chamber including a central perforated tube coaxially alignedwith said bore and containing a central passage of approximately thesame diameter as and opening forwardly and rearwardly to said bore so asto form a continuation of said bore, a booster propellant surroundingsaid tube, and said tube having ports through which said boosterpropellant is disposed in ignition relation to said bore, whereby whensaid primary round is fired said projectile travels forwardly throughsaid tube to expose said booster propellant to the propellant gas behindthe advancing projectile and thereby effect ignition of said boosterpropellant to generate additional high pressure propellant gas whichenters said bore behind said projectile to accelerate the latter throughsaid bore; and

said breech mechanisms including means for emptying and reloading saidfiring chambers.

19. A hypervelocity gun for firing individual elongate fixed chargeprimary ammunition rounds of fixed size and shape each containing aprimary propellant charge and a projectile and individual elongate fixedcharge booster ammunition rounds of fixed size and shape each containinga booster propellant, comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel includingmeans for transporting said primary ammunition rounds in succession to aprimary firing position wherein each primary round is coaxially alignedwith said bore;

a secondary breech mechanism along said barrel at a booster stationforwardly of said primary breech mechanism including means fortransporting said booster ammunition rounds in succession to a secondaryfiring position wherein the booster propellant within each booster roundis disposed in ignition relation to said bore at said booster station,whereby when a primary round is fired in said primary firing positionwith a booster round in said secondary firing position, the projectileof the fired primary round is propelled forwardly through said bore bythe high pressure propellant gas generated by the fired primary roundand the booster propellant within the booster round currently in saidsecondary firing position is ignited by said gas upon forward travel ofthe advancing projectile through said booster station to generateadditional high pressure propellant gas which enters said bore behindthe advancing projectile for accelerating the latter through said bore;and

means for driving said primary and secondary ammunition transport meansin timed relation to simultaneously locate primary and secondary roundsin firing position.

20. A hypervelocity gun comprising: a barrel containing a bore; aprimary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primarybreech mechanism; each of said breech mechanisms including an ammunitioncarrier;

the carrier of said primary breech mechanism containing a primary firingchamber and being movable to locate said primary chamber in anammunition infeed position and a firing position;

the carrier of said secondary breech mechanism confiring position; meansfor driving said carriers in timed relation to simultaneously locatesaid firing chambers in firing position; and

means for operating said driving means and firing means in timedrelation in such manner as to actuate said firing means in response toarrival of said firing chambers in firing position.

References Cited UNITED STATES PATENTS McArthur 89-8 Stafford 89-8Stanley 89-8 Schwager et al 89-155 Dardick 42-395 Treat 89-7 SAMUEL W.ENGLE, Primary Examiner US. Cl. X.R.

